Cable retrieving apparatus



Patented Aug. 25, 1953 UNlTED sures PATENT OFFICE t assure cmu: nmmvmo mm''us Ernest F. Axelen, Seattle, w. Application rimu u. 1951, se- No. zam

a Clims. (c. 294-102 l This invention relates to the retrieving oi' cables from inaccessible locations, and more particularly concerns an improved method and apparatus for retrieving broken or dropped cables standing in well casings and the like.

A common mishap in the drilling of water 'and oil wells, tor example, is the breaking oi' a drilling cable tar down inside the casing. Moreover, it is not uncommon to have to abandon a partially complete well becaus the broken cable and the drilling apparatus connected thereto cannot be recovered. In such cases the financial losses may be great, especiallyit the well bore has been carried to a considerable depth. To my knowledge no satisiactory apparatus or method has been proposed hereto- !ore to cope with this situation by enabling the operator to fish the broken cable section out of the casing.

The present invention is directed to a practical solution to the Ioregoing problem, and its general object is the provision oi reliable and easily operated cable retrieving apparatus tor fishing out broken cable sections i'rom well casings and the like.

A more specific object is cable retrieving apparatus of a portable, compact, llghtweight nature. which may b carried about conveniently by the drill operator from job to job, may be set up ready tor use at a moment's notice, and may be operated to complete a retrieving operation in a relatively short time.

Still another object of the present invention is apparatus of the type indicated which may be used to retrieve cables lying at great depths with substantially the same ease and convenience and in the same manner as those at relatively shallow depths. In that connection, the cable gripping elements o! the apparatus are so devised that they may be lowered into 'the well casing by means of retrieving apparatus cables until at the correct depth to obtain a hold on the broken cable end, whereby such gripping elements may then be manipulated or operated by means of the same retrieving apparatu cables to grip the broken cable and raise it out of the well' casing( Thus the attainable Operating depth of the apparatus is merely a matter ot the length of retrieving apparatus cable which may be payed out into the well casing. No rigid supporting members are needed to lower and operate the retrieving apparatus.

With the ioregoing in view, the invention !eatures a wedging member of a materially smaller cross section than the well caing interior, to

permit lowe'lng of such member into the casing past the upper end oi' a broken cable section standing therein. A receiving bell having a downwardly open interior terminates in a lower rim extending around the inside of the casing with a slight clearance therebetween, to permit lowering of such bell down into the casing past the upper end of the broken cable section-,until such upper end is received in 'the bell. The wedging member, suspended i'rom a retrieving cable, is then raised into the bell` to engage the broken cable therebetween. The interier of the bell is tapered upwardly, so that "a further liiting force applied to the wedging member by the retrieving cable causes the wedging member to wedge upwardly into the bell and henc outwardly against the broken cable held therebetween. Thus as the -retrieving cable is raised to exert increasing tension in the broken cable section gripped by the bell and wedging member, the trictional holding force exerted thereon correspondingly increases.

Prererably the inner or wedgingg member has an upper cable engaging portion which tapers upwardly at substantially the same angle as the bell interior, thereby to grip the cable uniformly therebetween over an appreciable portion of its length. At least one such wedging surface is provided with serrations which bite into the cable and oppose withdrawal thei-eo! from th grippirg elements. n

The foregoing and other features, objects, and advantages orthe invention will become more fully' evident from the following detailed description thereot by reference to the accompanying drawings illustrating the preferred i'orm of the apparatus for use in the retrieving of broken drilling cables lying in we'll casings. p

Figur-e 1 is a sectional side elevation 'oithe cable retrleving apparatus lowered into a well casing preparatory to srlpping the broken cable section. r

Flgure 2 is a similar view illustrating the relationship of the gripping elements at the suc-` assuming a slowspiral up the interior of the casing. due to the inherent tendency of the cable v section, as shown in Figure 1.

down into the well casing C to a location some-* what below the upper end of the broken cable The wedging member o somewhat resembles a plumb bob, having a pointed lower end for guiding it downward through the open spaces around the collapsed cable. The wedging member is Suspended from a retrieving cable !2. As shown in Figure 2, a sleeve M is brazed or welded on the lower end oi' the retrieving cable l2, and is received in a socket in the upper end of the wedging member o. The socket interior is threaded, and a threaded cap IS, apertured to pass the retrieving cable, is threaded down into the socket to hold the sleeve M therein, and thereby complete a strong connection between the retrieving cable and the wedging member The second step in the operation of retrieving the cable S is the lowering of a bell s down into the well casing to a location just above the lowered wedging member !0. The depth to which the bell s is lowered is not critical, the object merely being to receive an appreciable portion of the upper end of the broken cable section S inside the interior of the bell, as shown in Figure 2. In Figure 1, as shown by the arrow, the bell is in the process of being lowered to receive the broken cable section ther-ein. Whereas the wedging member piloting the operation is of a materially smaller cross section than the interior of .the well casing, so that it may be lowered freely into the space below the upper end of the broken cable without crushing the latter or turning its upper end downward. The diameter of the lower rim of the bell s is just slightly smaller than the interior of the well casing, so that the upper end of the broken cable will not escape past the outer edge of such rim, but will be directed thereby to pass into the interior of the bell, as shown.

The interior of the bell !8 is tapered upwardly. to form a conical wedging surface, preferably oi' aboutdegrees slope. Preferably the upper portion of the wedging member Io is likewise tapered at about the same angle, complementally to the interior of the bell. Thus after lowering or the bell to receive the upper end of the broken cable section, the next step of raising the wedging member o into the interior of the bell, as shown in Figure 2, causes a wedging action in which the cable is gripped between the two tapered surfaces, that in the bell and that on the wedging member. As the retrieving cable l2 is raised further, the wedging force between the two gripping elements increases because of Iriction thereof against the gripped cable. Thus the frictional grip on the broken cable section established by the two wedging members increases with tension in the retrieving cable !2. Annular grooves or serrations n' on the tapered portion of the wedging member n, being directed upwardly, improve its grip on the cable to prevent the lattcr's withdrawal from between the gripping elements, while in no way interfering with establishment of their hold on the cable initially.

`'wedging member may enter the bell alongside the largest cable to be received therein, whereas the upper end of the wedging member Io will not strike the upper throated portion of the bell,

even with the smallest diameter cable received in.

the bell alongside the wedging member. Of course, a range of sizes of retrieving bells and wedging members may be provided for Operations in well casings of difierent sizes, as needed.

The upper end of the bell !8 has a central opening or threat which continues upwardly into a tubular extension 20 threaded into the bell as shown. An apertured cap 22 is threaded on the upper end of the extension 20, and freely passes the retrieving cable l2 through its aperture, as shown -in Figure 2. A light cable 24 connected to a hook or eye 26 on the cap 22 permits raising and lowering the bell s independently of the wedging member o. The only function of the cable 24 is to lower the bell into its correct initial position relative to the upper end of the broken cable section S, so that the latter may be gripped in the bell by raising the wedging member o. After the broken cable section is gripped as in Figure 2, the entire raising operation is performed by reeling in the retrieving cable I2, which carries all of the load. The cable 24 is reeled in simultaneously merely to take up the slack therein. Obviously any attempt to reel in the cable 24 faster than the retrieving cable !2 would result in upward movement of the bell !8 relative to the wedging member o, hence release of the broken cable section gripped between these members. As the retrieving cable l2 carries the load during actual raising Operations, it is, of course, desirable to employ a retrieving cable which is at least as strong as the broken drilling cable S which is to be retrieved.

The cap 22 on the upper end of the tubular extension 20 serves the additional purpose oi' preventing the upper end of the broken cable section s from working out through the top of the bell when the latter is being lowered over it. If it were permitted to do so it might droop downward and become caught between the bell s and the casing, and thereby foul the apparatus. A lip s' around the upper periphery of the bell s is intended to prevent any objects from becoming caught between the bell and the well casing as the bell is being raised.

It will be seen, therefore, that the entire retrieving operation may be carried out quickly in a few simple steps, commencing with the initial lowering of thewedging member o to the location of the broken cable section standing in the well casing. If desired, the correct depth to which such wedging member should be lowered may determined in advance by a sounding operation consisting of the lowering of a plumb bob or other object and measuring off' the length of line from which the bob is Suspended when it initially strikes the broken cable section. Such measured length of sounding line would then represent the length of retrieving cable to be reeled oi'r in lowering the wedging member u to its correct initial position inthe casing. This initial sounding operation may be particularly desirable where the broken cable section lies at a great depth below around level, and it becomes correspondlngly difilcult, because o! the mass of retrieving cable payed out, to sense the point at which the wedging member begins to contact and rub along the broken cable section standing in the casing.

Because of the annular form of the bell I! with its ilared or scocplike lower end, the step of directing the upper end of the broken cable S into the interior of the bell on the first try is practically a certainty. Likewise the succeeding step of raising the wedging member Hi into the interior of the bell without ejecting the cable from the bell is also a simple matter. When the cable is gripped between the bell and wedging member it is more easily broken anew than released from between these elements, so firm is the hold caused by the wedging action. Moreover gripping pressure on the cable is evenly distributed over an appreciable portion of its length, that is between the tapered or conical wedging surfaces of the coacting retrieving elements, so that the gripped cable is not weakened by localized biting action and concentrated Stress.

If a steady upward pull on the retrieving cable !2 does not free the drilling` cable S so that it may be raised in the casing without again being broken, the operator will usually be successful in freeing it if he intermittently reiaxes and restores tension in the retrieving cable to work the broken cable or drilling apparatus carried by it free of any obstruction in the casing. II for any reason it becomes desirable to release the cable S during a retrieving operation this may be readily accomplished simply by slacking off tension in retrieving cable I 2 and applying lifting force to cable 24.

I claim as my invention:

1. Cabl retrieving apparatus for use in well casings and the like, comprising a wedging pilot member of a materially smaller cross section than the well casing interior less the cable` thickness, to allow clearance for lowering of such member into the casing past the upper end of a broken cable section standing therein, a receiving bell having a downwardly open interior terminating in a lower rim portion extending around the casing interior' with a slight clearance therebetween, means to lower such bell into the casing and past such upper end of the broken cable section to direct the same into said bell, means to lower 4 said wedging member down into the casing in adinto said bell to grip the cable.

2. Cable retrieving apparatus !or use in well casings and the like, comprising a wedging pilot member of a materially smaller cross section than F the well casing interior less the cable thickness, to allow clearance for lowering of such member into the casing past the upper end of a broken cable section standingtherein, a receiving bell in a lower rim portion extending around the casing interior with a slight clearance therebetween, means to lower such bell into the casing and past such upper end of the broken cable section to direct the same into said bell, and means to lower said wedging memberdown into the casing in advance o! said receivlng bell and to raise said wedging member into said bell and against the cable received therein, thereby to grip the cable between said wedging member andbell, the interior of said bell being tapered upwardly therein to constltute a wedging surface against which the cable is pressed by said wedging member subiected to increased lifting force by said raising means, thereby to increase the gripping pressure on said cable by wedging action accompanying such increase o! ilfting force.

3. Cable retrieving apparatus defined in claim 2, wherein the wedging member has an upper cable engaging portion which tapers upwardly at 'substantially the same angle as the bell interior to grip the cable wedgingly therebetween over an appreciable portion of its length.

4. Cable retrieving apparatus defined in claim 3 wherein at leastvone of the tapered wedging surfaces is serrated, th serrations being formed to bite into the cable and oppose withdrawal thereof from between such wedging surfaces while oflering minimum resistance to wedging action thereof against the cable.

5. Cable retrieving apparatus deiined in claim 3, wherein the wedging member has a downwardly tapered lower portion guiding such member to penetrate through the coiled upper portion of the broken cable standing in the casing when such member is lowered therein.

6. Cable retrieving apparatus foruse in well casings and the like, comprising a retrieving cable, a wedging pilot member carried by such retrieving cable tor raising and lowering thereof in the casing and being of a materially smaller cross section than the well casing interior less the cable thickness, to allow cleararice for lowering of such member into the casing past the upper end of a broken cable section standing therein, an annular receiving member apertured to pass said retrieving cable for lowering of said wedging member thereby into the casing in advance of said receiving member, and a separate cable !or raising and lowering of said annular member in the casing, said annular member having a lower rim extending around the casing in-' terior with a slight clearance therebetween to permit lowering thereot freely into the casing and past such upper end oi the broken cable section to direct the same into the interior of said annular member. whereby raising of said wedging member into said annular member by said retrieving cable effects gripping of the broken cable therebetween, the annular interior of said annular member being tapered upwardly therein to `constitute a wedging surface against which the' broken cable is pressed by said wedging member subjected to increased lifting force by said retrieving cable, thereby to increase the gripping pressure on said broken cable by wedging action accompanying such increase of lifting force.

7. Cable retrieving apparatus defined in claim 6, wherein the interior of the annular member tapers upwardly therein to a restricted throat and has a tubular upward extension thereon to receive the !ree end of the broken cable guided into the 'interior 'of such annular member and.

through such throat, the upper end o! said exhaving a downwardly open interior terminating tension being blocked oi! to prevent escape oi' the upper end of the bro (n c able and iouling the retrieving apparatus.

8; Apparatus tor retrieving a broken cabie standing in a well casing or the like, comprising a pilot member tormed to be lowered into the casing past the upper end of the broken cable standing therein, a 'retrieving cable to raise and lower said pilot member in the casing, and broken-cable encircling means loosely slidable in the casing and provided with an opening to pass and be guided by the retrieving cable slidably, thereby permitting said encircling means to slide by gravity down into the casing along the retrieving cable, said encircling means having an open lower end portion 'adapted to slip down over the upper end o! the broken cable and encircle such broken eable together with the pilot member in lowered position thereot, said pilot member being !ormed to lodge insaid opening and apply gripping pressure to the broken cable against a side of said opening automaticauy by exertion of lifting force on said pilot member by said reo trieving cable ERNEST F. AXELSEN.

No reference:: cited. I 

